As of last year, nearly $100 million in campaign funds sat idle in the accounts of former political candidates.

The California Democrat's bill — H.R. 1518, also known as (cue Elsa) the "Let it Go Act" — would force former federal candidates who aren't again seeking federal office to "dispose of" lingering campaign money within six years of their last race.

After first paying off all outstanding debts, candidates' campaigns could disgorge extra cash by cutting refunds to contributors, transferring it to political party committees or donating it to nonprofit groups, according to the bill.

"If a person is not going to run for office, this money shouldn't be be able to sit around forever," Takano told the Center for Public Integrity.

Takano says he's particularly concerned about members of Congress leaving office, becoming lobbyists and maintaining political campaign accounts — the money in which could be given to other candidates.

"It becomes an extension of your lobbying salary and another tool for leverage on the political process," he said.

So far, Takano's bill, which he formally introduced last month, has no co-sponsors. And the House Administration Committee, to which the bill has been referred, has not yet set a hearing date for it.

Since entering Congress in 2013, Takano has yet to see any of the 17 bills he's introduced signed into law, although his staff notes that he has helped influence larger pieces of successful legislation, including him adding language to one bill that increased the number of medical residencies at Veterans Affairs facilities.

Despite his limited legislative victories, Takano expressed confidence that the Let it Go Act would attract support from both Republicans and Democrats, particularly those in Congress who are "trying to help rebuild the reputation of the institution."

Ex-congressmen offer different reasons for why they've retained huge amounts of campaign cash years after last serving.

Former Democratic Sen. Evan Bayh of Indiana told the Center for Public Integrity last year that he didn't want to "foreclose any possibilities at this time" because "the future is difficult to predict."

Bayh, who decided against seeking another term in 2010 and is now an adviser at law and lobbying firm McGuireWoods, had nearly $10 million left in his old campaign account as of Dec. 31. Since leaving the Senate, he has been courted to run again for political office but has repeatedly declined, most recently opting against a bid for governor of Indiana.

For his part, former Rep. Mark Foley, R-Fla., who reported more than $1.2 million left in his congressional account as of March 31, has said he is also weighing future political prospects. In 2006, he resigned from Congress under pressure from colleagues after sending sexually explicit messages to boys serving as congressional pages.

"After the resignation, I would have given it slim odds that I’d ever run again,” Foley said last year. “But I’ve had people tell me since, ‘Your public service was sterling aside from a bump in the road.'"

To date, Foley has announced no plans to run for office.

Then there's former Rep. Joe Kennedy II, a Massachusetts Democrat who hasn't served in Congress in 16 years.

As of Dec. 31, Kennedy's long-unused campaign fund had about $2.6 million in its coffer. That includes more than $176,000 in interest, dividends and capital gains the committee earned through investments during the fourth quarter of 2014.